. The Bell System technical journal . n, the opera-tion of a carrier system com|)rising three carrier terminals designatedas /I, /J and C with a remote control station designated as .-11 locatedat the load dispatchers office and separated from the carrier terminalby several miles of physical telephone circuit is as follows. Each ofthese stations may communicate with any of the other between A, B and C is carried on over carrier cir-cuits; communication between ,1 and .11 is carried on oxer the jihysical \y ///(,// l(.5 (irriiit
. The Bell System technical journal . n, the opera-tion of a carrier system com|)rising three carrier terminals designatedas /I, /J and C with a remote control station designated as .-11 locatedat the load dispatchers office and separated from the carrier terminalby several miles of physical telephone circuit is as follows. Each ofthese stations may communicate with any of the other between A, B and C is carried on over carrier cir-cuits; communication between ,1 and .11 is carried on oxer the jihysical \y ///(,// l(.5 (irriiit wliilt- (■oinmimicKion lutwirii .li, li and C is rarrird on i>\vrcimiits whifh arr idiiipositl of a cirrit-r cirriiil ami a pinsical cir-ruit <)|Hratiiij; in taiuU-in. Wlun in llu- or iiDn-oiK-rali-dconditions, earli of tlusi carrier is set ii)) lo reci-i\e a sij^nalon fri(]iifncy Fu lint wlit-n tlie rert-ivcr is reinmed from the swilcli-hiH)k at any station to initiate a call, the carrier tenninai corre-. Fig. l^—110 Coupling Condensers Used for Coupling Carrier Circuit to a110 Power Line sjiondini; to that telepiione is autonialicalK set up to transmit onfrecjuency Fi and receive on frequency F«. When the ringing kc\ isoperated, pulses of frequency Fi are sent out and received at all of theother carrier terminals. At the called station these pulses operatea selector relay and ring the l>ell, and when the operator removeshis receiver from the switch-hook to answer the call, his carrier terminalis automatically set up to transmit on frequency F> and recei\e on 166 BELL SYSTEM TECHNICAL JOURNAL frequency Fi. This switching of the transmitting and receiving cir-cuits from one frequency to another is necessary where more thantwo stations arc operated on the same system and it is desirable forevery station to \k> able to call every other station without routingthe call through a central point. If station .4i is connected with statio
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
